Self-Assembly and Characterization of Cyano-Bridged Bimetallic [Ln-Fe] and [Ln-Co] Complexes (Ln = La, Pr, Nd and Sm). Nature of the Magnetic Interactions between the Ln3+ and Fe3+ Ions.

Two structural series, including seven isomorphous heterodinuclear complexes, [Ln(DMSO)4(H2O)3(μ-CN)M(CN)5]·H2O ([La-Fe] (1), [Pr-Fe] (2), [Pr-Co] (3), [Nd-Fe] (4), [Nd-Co] (5), [Sm-Fe] (6) and [Sm-Co] (7)), and seven isostructural 2-D stairlike cyano-bridged bimetallic assemblies, [Ln(DMSO)2(H2O)(μ-CN)4M(CN)2]n ([La-Fe]n (8), [Pr-Fe]n (9), [Pr-Co]n (10), [Nd-Fe]n (11), [Nd-Co]n (12), [Sm-Fe]n (13) and [Sm-Co]n (14)) (DMSO = dimethylsulfoxide), have been rationally prepared by a facile approach, a ball-milling method, and characterized by X-ray diffraction and magnetic measurements. The isomorphous structures, in conjunction with the diamagnetism of the Co3+ and La3+ ions, allow an approximation to the nature of coupling between the iron(lll) and lanthanide(lll) ions in the Ln3+-Fe3+ complexes. The Ln3+-Fe3+ interaction is ferromagnetic for the dinuclear [Pr-Fe] (2), [Nd-Fe] (4), and [Sm-Fe] (6) systems and for the 2-D [Pr-Fe]n (9), [Nd-Fe]n (11), and [Sm-Fe]n (13) assemblies. [ABSTRACT FROM AUTHOR]